SLC40A1 and obesity due to melanocortin 4 receptor deficiency: Obesity - induced adipokine disorders (such as increased leptin) upregulate hepatic hepcidin through the JAK2/STAT3 signaling pathway, inhibiting FPN-mediated iron efflux and leading to the accumulation of free Fe2+ in the liver (Eder et al., 2020; Arfin et al., 2023).